Device for automatically correcting the position of an original in anautomatic copying machine

ABSTRACT

In an automatic copying machine of the type having an original circulation repeat path for producing a number of duplicates, a device for automatically correcting the orientation of the original during circulation on the repeat path endless belt comprising the disposing of original sensing switches on opposite sides of the repeat path upstream of the duplicating station, which switches lie on a line normal to the direction of travel of the original so that when the original is correctly oriented on the belt, the switches are simultaneously actuated, but when the original is incorrectly oriented, one switch will be actuated before the other. The time lag between the actuation of the switches is used to actuate a correcting system which through a bearing nut mounted on a threaded portion of a DC motor output shaft moves one end of one of the belt mounting rollers whose other end is pivoted so as to change the length of one side of the belt with respect to the other side, thus reorienting the original before entry into the duplicating station.

United States Patent 1 Kobayashi et al.

[ Aug. 28, I973 DEVICE FOR AUTOMATICALLY CORRECTING THE POSITION OF AN ORIGINAL IN AN AUTOMATIC COPYING MACHINE [75] Inventors: Yugoro Kobayashi,Suginami-ku,

Tokyo, Tsutomu Yamagami, Arakawa-ku, Tokyo, both ofJapan [73] Assignee: Ricoh Co. Ltd., Tokyo, Japan [22] Filed: Sept. 21, 1972 21 Appl. No.: 290,875

[52] US. Cl 355/109, 271/49, 271/59, 355/73, 355/76, 355/102 [51] Int. Cl. G031) 27/12 [58] Field of Search 355/109, 110, 102, 355/73, 76, 91; 271/49, 59

I 56] References Cited UNITED STATES PATENTS 3,709,596 1/1973 Ulmer 271/49 X 3,310,304 3/1967 Foias et al. 271/49 X Primary ExaminerRichard L. Moses Attorney-Henry T. Burke et al.

[5 7] ABSTRACT In an automatic copying machine of the type having an original circulation repeat path for producing a number of duplicates, a device for automatically correcting the orientation of the original during circulation on the repeat path endless belt comprising the disposing of original sensing switches on opposite sides of the repeat path upstream of the duplicating station, which switches lie on a line normal to the direction of travel of the original so that when the original is correctly oriented on the belt, the switches are simultaneously actuated, but when the original is incorrectly oriented, one switch will be actuated before the other. The time lag between the actuation of the switches is used to actuate a correcting system which through a hearing nut mounted on a threaded portion of a DC motor output shaft moves one end of one of the belt mounting rollers whose other end is pivoted so as to change the length of one side of the belt with respect to the other side, thus reorienting the original before entry into the duplicating station.

6 Claims, 5 Drawing Figures Patented Aug. 28, 1973 3 Sheets-Sheet 1 Patented Aug. 28, 1913 3,754,826

3 Sheets-Sheet 2 Patented Aug. 28, 1973 3,754,826

25 Sheets-Sheet 6 DEVICE FOR AUTOMATICALLY CORRECTING THE POSITION OF AN ORIGINAL IN AN AUTOMATIC COPYING MACHINE BACKGROUND OF THE INVENTION This invention relates to a device for automatically correcting the position of an original in an automatic copying machine of the type in which the original is repeatedly circulated to produce a large number of duplieates of the original.

Automatic copying machines of the character described above usually have a disadvantage in that after the initial printing the original is transferred to a belt for repeated circulation during subsequent printings and the position of the original gradually deviates from the normal position as it is circulated many times in the machine. Since this disadvantage is of the nature such that misalignment of the original with respect to the belt increases in degree as the number of times of the travel of the original with the belt increases, the number of duplicates that can be produced by repeatedly circulating the original has been limited to about 20 to 30 sheets. Thus, the problem has arisen of how to increase the practical value of the copying machines of the type described by increasing the number of duplicates that can be produced thereby.

The present invention has as its obect the provision of a device for automatically correcting the position of the original in an automatic copying machine of the type in which the original is repeatedly moved in eirculation which obviates the aforementioned disadvantage of the prior art, and which permits accurate duplicates of the original to be produced in any number as desired without practically any limits being placed on the'number of duplicates produced. I

SUMMARY OF THE INVENTION According to the. present invention, there is provided a device for automatically correcting the position of the original in an automatic copying machine which comprises two switches that are disposed on the original circulation repeat path so as to be actuated simultaneously by the leading edge of the original when the original is correctly positioned with respect to the original conveying belt but such that one switch will be actuated with a time lag when the original is not correctly positioned with respect to the original conveying belt, and means which remains inoperative when both the switches are actuated simultaneously by the original and which is rendered operative when one switch is actuated with a time lag whereby the repeat length on the left or right side of the circulation repeat path can be adjusted relative to each other. The device is efiective automatically to correct the position of the original on the original conveying belt, thereby maintaining the original in a correct position on the belt.

Other and additional objects as well as features and advantages of the invention will become evident from the description set forth hereinafter when considered in conjunction with the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view illustrating an automatic copying machine of the type provided with an original circulation repeat path;

FIG. 2 shows an original disposed in a correct position relative to the original conveying belt in the machine of FIG. 1;

FIG. 3 shows the original of FIG. 2 disposed in a position in which it deviates from its correct position or its longitudinal axis is out of alignment with the longitudinal axis of the belt FIG. 4 is a view illustrating means for automatically detecting the position of the original according to this invention; and

FIG. 5 is a view illustrating means for correcting the position of the original which is adapted to be actuated by a signal from the detection means.

DETAILED DESCRIPTION OF THE INVENTION An automatic copying machine of the prior art will be described with reference to FIG. 1.

In FIG. 1 is shown a housing I containing a sheet feed belt 2 trained about a transparent printing cylinder 4 having a light source 3 mounted therein, and a drive roller 5 and a plurality of guide rollers 6. Another belt 8 is trained about a suction tank 7 and guide rollers 15 to constitute a repeat circulation path for an original to be duplicated, while 9 designates a photosensitive sheet separating tank, 10 is a developing section and 11 is a photosensitive sheet tray.

When the original 12 is inserted through an inlet port as shown, a photosensitive strip is automatically paid out from a photosensitive strip roll 13, and a photosem sitive sheet I3 ofa size corresponding to the length of the original 12 is severed from the strip by a cutter I4. The photosensitive sheet 13 and the original 12 are su perposed one over the other and moved along the sheet feed belt 2. The overlapping photosensitive sheet 13' and the original 12 then move between the belt 2 and the printing cylinder 4, and the image of the original 12 is printed on the photosensitive sheet 13' is attracted to the separation tank 9, developed at the developing section 10 and finally ejected on to the photosensitive sheet tray 11.

Meanwhile, the original 12 is drawn by suction from the photosensitive sheet by means of the suction tank 7 and transferred from the sheet feed belt 2 to the belt 8 which constitutes the repeat circulation path of the original. Once transferred to the belt 8, the original 12 moves with the belt 8 and returns to the starting position on the sheet feed belt 2 where it is brought to an overlapping relationship with another photosensitive sheet which has been severed from the photosensitive strip roll 13 by the cutter 14. The overlapping original and photosensitive sheet are again moved to the printing section. In this way, the original 12 is moved along the circulation repeat path many times till a predetermined number of duplicates have been produced.

As the original 12 is repeatedly moved with the belt 8, the original 12 will tend to deviate (as shown in FIG. 3) from its normal position on the belt (shown in FIG. 2) such that its longitudinalaxis tends to be brought out of alignment with the longitudinal axis of the belt 8, if the belt and eyliders are not dimensioned accurately. Thisphenomenon may cause the image of the original reproduced on the photosensitive sheet to be out of alignment with the copy sheet, or, in extreme cases, the image may be partially reproduced on the photosensitive sheet.

In order to obviate this disadvantage, it is suggested besides increasing the dimensional accuracy of the parts concerned, to adjust the position of one of the guide rollers 15 for the belt 8 relative to the positions of other rollers 15 so as to vary, for example, the repeat length of the right side of the circulation repeat path from the repeat length of the left side thus continuously compensating for the deviation of the original 12 to one side and permitting it to be continuously positioned ac curately on the belt 8. However, it is required to effect a readjustment each time there is a change in the quality, degree of curling and size in the originals used.

An embodiment of the present invention for use in such a machine will now be described with reference to FIG. 4 and FIG. 5. Two microswitches l6 and 16', positioned as shown in FIG. 1 are mounted in the original circulation repeat path and are disposed in side-by-side relationship so that the original 12 moving with the belt 8 may come into contact with the switches at its leading end.

The switches 16 and 16' are each disposed near one of the opposite side edges of the repeat path and on a line which is normal to the direction of movement of the original, so that the two switches are engaged and actuated simultaneously by the leading end of the original when the latter is disposed in the correct position. However, the switches will be engaged and actuated with a difference in time when the original is not disposed in the correct position. 17 designates a switch for connecting and disconnecting the switches 16 and 16 to a power source 18.

When the original 12 is moved in the direction of an arrow p in FIG. 4, the original 12 first pushes the switch 17 to connect the switches 16 and 16' to the power source 18. However, the original 12 is not brought into contact with the switches 16 and 16 as yet and the switches 16 and 16' are each in a position shown in a solid line in FIG. at this time, so that the voltage from the power source 18 is not connected to a DC motor 19 which therefore remains inoperative.

When the original 12 moves farther and its leading end is brought into engagement with the switches 16 and 16' and actuates them simultaneously, the two switches are each brought to the positions shown in the broken lines and connected to the same terminal of the power source 18, so that the motor 19 is still not rendered operative.

However, if the original 12 is disposed in a position which deviates from its correct position as shown in FIG. 3, the switch 16 will be engaged and actuated earlier than the switch 16 by the leading end of the original 12. At this time, the switch 16, as shown in FIG. 5, is brought to the broken line position in which it cooperates with the switch 16' in the solid line position to supply a voltage from the power source 18 to the DC motor 19. As a result, a bearing nut 21 is moved through a threaded member 20 connected to the shaft of the DC motor 19 so as to adjust the position of one of the rollers 15, journalled at one end thereof in the bearing nut 21, relative to the positions of the other rollers 15. This adjustment is carried out continuously till the other switch 16 is actuated by the leading end of the original 12. Upon actuation of the switch 16', the two switches 16 and 16' are both in the broken line position, thereby cutting off the power source voltage to the DC motor 19.

It will be seen that the time interval during which the DC motor 19 is rendered operative may vary depending on the time lag between actuation of one of the switches 16 and 16' relative to the actuation of the other switch by the leading end of the original 12, that is, in accordance with the degree of deviation of the po sition of the original 12 from its correct position on the belt 8. Stated differently, if the position of the original 12 deviates greatly from its normal position, the time lag will be great and the DC motor 19 will remain operative for a relatively long interval of time, but if the position is almost normal, the time lag will be small and the DC motor will remain operative for a short interval of time.

When the switch 16' is actuated by the leading end of the original earlier than the switch 16, a voltage from the power source 18 is also impressed on the DC motor 19. In this case, however, the polarity of the voltage impressed on the DC motor 19 is reversed as can be seen from FIG. 5, so that the motor 19 is rotated in the reverse direction and the adjustment of the roller 15' will be effected oppositely to the adjustment effected as aforementioned. In FIGS. 2 to 5, 22 designates suction openings formed in the suction tank 7, disposed between various belt members 8A of the belt 8.

From the foregoing description, it will be appreciated that the present invention permits deviation of the original from its correct position to be automatically detected and the position of the original to be automatically corrected by a signal produced as the result of detection of the deviation by a simple mechanism, whereby duplicates of the original can be produced in correct form with no limits being placed on the number of duplicates produced in a repeat operation. It will also be appreciated that the belt members 8A are of a somewhat elastic material to permit varying the path length on one side of the belt 8 with respect to the other side and that the roller 15 is mounted at the end opposite that journalled in the bearing nut 21, in a bearing 23, which permits some lateral pivoting of the roller.

What is claimed is:

l. A device for correcting the orientation of an original to be duplicated during circulation in an automatic copying machine of the type having an original circulation repeat path for producing duplicates, said device comprising:

a. an endless elastic belt means for continuously circulating the original around a repeat path and through a duplicating station;

b. a plurality of rollers mounting said belt means for continuous circulation therearound, one of said rollers being pivotable at one end so as to permit changing the length of one side of said repeat path with respect to the other side; first and second switch means disposed on opposite sides of said repeat path upstream of said duplicating station in such manner that when said original is correctly oriented on said belt means while passing, said first and second switch means are actuated simultaneously thereby but when said original is incorrectly oriented an indicative time lag will occur between the actuation of each switch;

(I. power means connected in circuit with said first and second switch means and actuated during the occurrence of a time lag between the actuation of each switch; and

e. correcting means operated by said power means for pivoting said one roller to change the length of one side of said repeat path during the occurrence of a time lag.

2. A device as in claim 1 wherein said power means comprises an electric motor having an output shaft and said correcting means comprises a threaded member connected to said output shaft and a movable bearing nut mounted for movement on said threaded member and having the end of said one roller opposite the pivoted end journaled therein.

3. A device as in claim 1 wherein said power means comprises:

f. a DC motor having one input connected to said first switch means and the other input connected to said second switch means; and t g a DC power source having one side connected to a first pole of each of said switches and the other side connected to a second pole of each of said switches.

4. A device as in claim 1 further comprising a third switch means disposed along said repeat path upstream of said duplicating station and actuated upon the passage of the original and having a first pole connected to one side of said DC source and a second pole con nected to the second pole of each of said first and sec ond switches.

5. A device as in claim 1 wherein said belt means comprises a plurality of elastic belt members arranged side-by-side to form said repeat path.

6. A device as in claim 1 wherein said first and said second switch means are disposed opposite each other across said repeat path on a line normal to the direction of movement of said original thereon. 

1. A device for correcting the orientation of an original to be duplicated during circulation in an automatic copying machine of the type having an original circulation repeat path for producing duplicates, said device comprising: a. an endless elastic belt means for continuously circulating the original around a repeat path and through a duplicating station; b. a plurality of rollers mounting said belt means for continuous circulation therearound, one of said rollers being pivotable at one end so as to permit changing the length of one side of said repeat path with respect to the other side; c. first and second switch means disposed on opposite sides of said repeat path upstream of said duplicating station in such manner that when said original is correctly oriented on said belt means while passing, said first and second switch means are actuated simultaneously thereby but when said original is incorrectly oriented an indicative time lag will occur between the actuation of each switch; d. power means connected in circuit with said first and second switch means and actuated during the occurrence of a time lag between the actuation of each switch; and e. correcting means operated by said power means for pivoting said one roller to change the length of one side of said repeat path during the occurrence of a time lag.
 2. A device as in claim 1 wherein said power means comprises an electric motor having an output shaft and said correcting means comprises a threaded member connected to said output shaft and a movable bearing nut mounted for movement on said threaded member and having the end of said one roller opposite the pivoted end journaled therein.
 3. A device as in claim 1 wherein said power means comprises: f. a DC motor having one input connected to said first switch means and the other input connected to said second switch means; and g. a DC power source having one side connected to a first pole of each of said switches and the other side connected to a second pole of each of said switches.
 4. A device as in claim 1 further comprising a third switch means disposed along said repeat path upstream of said duplicating station and actuated upon the passage of the original and having a first pole connected to one side of said DC source and a second pole connected to the second pole of each of said first and second switches.
 5. A device as in claim 1 wherein said belt means comprises a plurality of elastic belt members arranged side-by-side to form said repeat path.
 6. A device as in claim 1 wherein said first and said second switch means are disposed opposite each other across said repeat path on a line normal to the direction of movement of said original thereon. 